Synthesis of activated carbon-based amino phosphonic acid chelating resin and its adsorption properties for Ce(III) removal

Abstract

This work aims to investigate the adsorption of Ce(III) onto chelating resin based on activated carbon (CRAC). The CRAC adsorbent was prepared from activated carbon (AC) followed by oxidation, silane coupling, ammoniation and phosphorylation, and characterized by Fourier transform-infrared spectrometry, nitrogen adsorption measurements and scanning electron microscopy. The effects of solution pH, adsorbent dosage and contact time were studied by batch technique. Langmuir and Freundlich isotherms were used to describe the adsorption behaviour of Ce(III) by CRAC, and the results showed that the adsorption behaviour well fitted the Langmuir model. The maximum uptake capacity (q_max) calculated by using the Langmuir equation for cerium ions was found to be 94.34 mg/g. A comparison of the kinetic models and the overall experimental data was best fitted with the type 1 pseudo second-order kinetic model. The calculated thermodynamic parameters (ΔG°, ΔH° and ΔS°) showed that the adsorption for Ce(III) was feasible, spontaneous and exothermic at 25–45 °C. The CRAC showed an excellent adsorptive selectivity towards Ce(III). Moreover, more than 82% of Ce(III) adsorbed onto CRAC could be desorbed with HCl and could be used several times.

Keywords:

• activated carbon
• chelating resin
• adsorption
• cerium
• kinetic

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Public Service Project of the Chinese Ministry of Land and Resources [201311024], the National Natural Science Foundation of China [41372367] and the Fundamental Research Funds for the Central Universities [CUGL150806], China University of Geosciences (Wuhan).